Charles m



I l l N. PETERS, PHOTO-LITHOGRAPHER, WASHINGTON, D C.

of having the ordinary propcllers, withptheir driving mechanism, applied to them.

@eine .fatesa-tmt @office CHA RLEs M. OH'ARA, or LONDON, ENGLAND.

Letters Patent No. lO,460, AcZaAteol November 5, 1867; antcdaed October 26, 1867.

IMPROVBD PROPELLER POR VBSSELS.

titte rigehnle referrer tu in ligase htte'rs tant transiting ant nf tige` sami.

TO ALL WHOM'IT MAY CONCERN:

Be it known that I, CHARLES M. OHARA, of London, Englandhave invented a iiew and Improved Propellcr for Vessels; and I do hereby declare thatthe following is a full, clearan l exact description thereof, which will enable others skilled in the art to make and use the same, reference. being-had to the accompanying drawings, forming part of this specication. I

This invention consists of two oscillating propellers, of sector form, arranged in connection with steam engines of peculiar construction, whereby the propellers are acted upon bythe motor in the most direct manner possible, and a great amount of friction avoided, compactness of working parts obtained, and also economy in construction. In the accompanying sheet of drawings- Figurel is a side sectional view of my invention applied to a vessel, taken in the line a: :11, fig. 2.

Figure 2, a rear view of the same.

Figure 3, a rear view of. the same shown applied as side propeller-s. f I

Figures 4 and 5, views showing propellers of different sizes, or comprising different portions of a circle.

Similar letters of reference indicate corresponding parts.

A represcnts the stern portion of a'vessel, havingopenings or chambers B, one at cach side ofthe keel, to receive the propeller-s C C. 4These Propellers are of sector form, and may comprise a greater'or less portion of a circle, as shown in gs. 4 and 5. A quadrant, or one-quarter of a circle, as shown in fig. 1, would probably be as desirable a form as any. The propellers may be Aconstructed of metal plate, and be hollow, or they may be of wood, and either hollon1 or solid. They are each hung on separate shafts, a, or may be placed loosely on one and the same shaft.

D represents a piston-rod ofA circular form, and attached firmly to the propeller C, as shown clearly in fig. 1. This piston-rod is concentric with the shaft a of the propeller, and passes through a' steam-chamber, E, which performs the same function as the steam-cylinder of an ordinary steam engine.

The chamber E is of circular form in its transverse section, but is of` curved form longitudinally, so as to be concentric with the piston-rod D, as shown clearly i'n iig. 1.

F is the piston, secured on the piston-rod, and working within the chamber E in the same way as the piston of an ordinary steam engine, the steam being admitted in E alternately, at opposite sides of the piston, and expanded or condensed at the termination of each strokc, as usual. l

In iig. 1 a small supplementary engine, G, is shown, for operating the valves, and also for equalizing the movement of the propeller. This, however, is not a novel feature, in itself` considered, and forms no part of this invention.

Each propeller is provided with an engine like the one described, and the two propellers move alternately in opposite directions;

It will be seen, from thc above description, that the steam or motor is applied in the mostl direct manner possible to the propcllers, and the friction attending the operation of connecting-rods, cranks, die., entirely avoided. vThe dispensing with these various parts renders the mechanism extremely simple and compact, so that it occupies but comparatively little space, and renders it capable of being applied to vessels which will not admit To the rear side of each propeller there is attached an adjustable plate, H, projecting outwards at right angles therefrom. (See figs. 1 and 2.) These plates serve to render the operation of the Propellers more Veilicicnt in their action against the water, preventing the movement of the water upward as the Propellers move backward, and the rear sides oi' the propellers are made concave in their horizontal section, in order to prevent a too ready displacement of the water laterally during said backward movement of the propeller-s. This also materially augments the driving action of the propcllers, while it occasions no loss of power by lift The heightof the water-line or level is indicated in blue, and the full stroke ofthe propellers will be seen by referring to fig. 1, the extent of the forward stroke being indicated in red outline, and the extent of the backward stroke indicated in black. v

In order to back a vessel, or to give a reverse propelling action to the Propellers, the latter are moved back so as to operate at the rear of the chambers B, steam being admitted into theA steam-chambers E in suoli a manner to e'ect this result.

These propellers may be used at the stern of a vessel, as shown in iigs. -1 and 2, o1" at the sides thereof, as shown in g: 3. The principle of operation is the same in either case.

What I claim as new, and desire to secure by Letters Patent, is

1. A propeller, for vessels of navigation, made of sector form, and hung or suspended, so as to operate o1' oscillate in a vertical planle, substantially as shown and described.

2. Driving or operating the propellers by means of engines, the cylinders orsteam-chambexs of which arc of curved form longitudinally, and provided with circular piston-rods, substantially as shown and described.

3. The plates H, in combination with the oscillating propellers C C, substantially as and for the purpose specified. i f

CHARLES M. OIIARA.

Witnesses:

WM. F. MeNAMAnA, GEO. II. KNIGHT.. 

